1. Field of the Invention
The present disclosure is related to colorant compounds isolated from a reaction of Genipa americana juice, genipin or genipin analogs and an amine, compositions comprising the same, and methods of making and using the same.
2. Background of the Invention
Distrust of consumers in the use of synthetic colorants, mainly because of their toxicity, has led to the research and development of natural color compounds. These compounds have been utilized for many centuries, but recent technology advances allowed these colorants to be industrially and commercially viable and be able to compete with the synthetic ones. See “Market Brief in the European Union for selected natural ingredients derived from native species; Genipa americana,” presented in United Nations Conference on Trade and Development (2005). Internationally, natural colours such as blue and black colorants of Genipa americana are used by both the food, the cosmetics and the textile industry.
Methods of preparing blue colorants have been reported. For example, a method to make a pH stable blue colorant, derived from the mix of unprocessed raw juice obtained from Genipa americana fruit pulp and glycine, was described in Echeverri et al. (U.S. Pat. No. 7,927,637), the content of which is incorporated herein by reference in its entirety. Other examples of preparing blue colorants include JP Patent publication Nos. 52053932A2 and 52053934A2, H. Okuyama et al., which describe a blue-violet colorant made from a spontaneous reaction of primary amines with genipin; and Wu et al (WO 2009/120579), which describes mixing the Genipa americana juice with other fruit juices (e.g. watermelon) and amino acids. These existing methods generally use the resulted crude mixture without further purification, possibly due to the difficulty recognized in the art for purifying the mixtures. See Touyama R. et al., Studies on the Blue Pigments Produced from genipin and methylamine. I. Structures of the Brownish-Red Pigments, Intermediates Leading to the Blue Pigments, Chem Pharm. Bull 42, 66, 1994 (the blue pigment derived from a reaction of genipin or structural analogs and amino acids have been “found to be an intractable mixture of high molecular polymers on the basis of its chromatographic behavior, un-analyzable 13C-NMR spectrum and by molecular weight measurements”). There has been a limited description of the blue pigment material molecular structure since this material is almost soluble only in water due to its very high polarity which results in hard TLC monitoring. A polymer of 9000 molecular weight has been reported (see H. Jnouye, Y. et al., 26th Symposium on the Chemistry of Natural Product, Kyoto, Abstr. pp 577-584, 1983). More recently, Wu and Horn (U.S. Pub. No. 2013/0115252) described a method of enriching genipin from Genipa americana and the uses of enriched genipin material. However, the “genipin-rich extract” is disclosed as being 30-97% (w/w) genipin with the remainder of the composition including moisture, fat, small amounts of acids and nitrogen-containing compounds, with the balance being carbohydrates (see U.S. Pub. No. 2013/0115252, page 3, left column).